MICROSCOPY Vol.46▶No.2 2011
â– Feature Articles: Tumor Initiating Cells and Their Regulation

Vascular niche for cancer stem cells and angiogenesis

Nobuyuki Takakura

Department of Signal Transduction, Research Institute for Microbial Diseases, Osaka University

Abstract: Blood vessels have a fundamental role in supplying oxygen, nutrient, inflammatory cells. Moreover, they are also involved in organ generation and maintenance. For instance, blood vessels provide a niche, a microenvironment that supports self-renew of stem cell population in normal organ. This concept expands to the field of cancer biology and it has been suggested that cancer stem cells are located in a perivascular region for their proliferation. Moreover, through cell-to-cell contact, arteries guide adequate migration direction of neurite. Therefore, analysis of molecular mechanism in blood vessel formation and maintenance is important to develop a strategy for the regulation of tissue regeneration. In usual concept of angiogenesis, it has been widely accepted that endothelial cells from preexisting vessels sprout and proliferate monotonously during angiogenesis; however, recently at least three different endothelial cells such as tip, stalk and phalanx cells have been suggested to be involved in new blood vessel formation in sprouting angiogenesis. In such heterogeneity of endothelial cells, involvement of stem cell system is argued in preexisting blood vessels.

Key words: Endothelium, vascular niche, cancer stem cell